vSphere ESXi 5.1 (free) Installation Error

I'm attempting to install vSphere ESXi 5.1 (free version) from a USB thumb drive as this computer doesn't have a CD/DVD drive.  I've created a bootable USB drive, copied the ISO to it and configured my BIOS to boot from USB.  Unfortunately, I get the following error:

3>Command line is empty.

<3>Fatal error: 32 (Syntax)

I've even tried using tools to create the USB thinking maybe I did something wrong such as:

http://www.linuxliveusb.com/

I did find the following article:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2007475

But the only option my BIOS has related to UEFI is under "Boot mode select" and the only options it offers are below and neither of them seem to make a difference.

• UEFI
• Legacy + UEFI

Any ideas on how to get this working?